Seed dressing with pesticides to control many kinds of wheat diseases and insect pests

Wheat is the second largest food crop after rice in China. China has a vast territory and complex geographical conditions. There are many kinds of wheat diseases and insect pests, the occurrence range is large, and the harm is very serious. According to statistics, wheat production in China is reduced by about 30% every year due to the occurrence of various diseases and insect pests. The prevention and control of autumn sowing time can get twice the result with half the effort in controlling the damage of many kinds of diseases and insect pests of wheat. In recent years, with the strong promotion of agricultural departments at all levels, a large area of chemical seed dressing has been carried out to control autumn seedling diseases and insect pests, so that wheat diseases and insect pests can be effectively controlled throughout the year.

In order to do a good job of seed dressing of autumn sowing winter wheat in China in 2010-11, the following control suggestions were put forward.

1. The main control objects and main areas for seed dressing of wheat sowing in autumn

1. Wheat stripe rust, and treatment of wheat powdery mildew. The main areas are the summer area and autumn seedling area of wheat stripe rust.

two。 Soil-borne diseases are mainly sheath blight, total erosion and root rot. It mainly includes Jiangsu, Henan, Shandong, Anhui, Hebei, Shaanxi and other areas with high soil moisture and the new occurrence of wheat total erosion disease in the lower reaches of the Yangtze River and Huang-Huai basins in China.

3. The main systemic infection diseases are stem smut, loose smut and fishy smut. According to the amount of bacteria in the soil and the incidence of varieties in previous years, there is no fixed occurrence area.

4. Underground pests are mainly grubs, mole crickets and golden needle worms. It occurs in all the main wheat planting areas, and whether seed dressing should be decided according to the situation of the previous year. Underground pests generally bite the roots and stems of wheat in the autumn seedling stage and after turning green, resulting in lack of seedlings and broken ridges.

Second, how to mix seeds with chemicals

The method of regional control should be adopted in the control of wheat diseases and insect pests by seed dressing, and the types, application methods and dosage of seed dressing chemicals should be determined according to the occurrence types of local diseases and insect pests.

1. Triazole fungicides with internal absorption and conduction and long lasting effect, such as triadimefon (also known as triadimefon), triazole (also known as hydroxyrust), propiconazole, terrazole, diniconazole, etc., are selected for the control of wheat stripe rust in summer and overwintering areas. For the areas where many kinds of diseases and pests occur simultaneously and alternately at seedling stage, fungicides and insecticides should be mixed with seeds to achieve the purpose of controlling both underground pests, sucking worms, aphids and other seedling pests. The effective concentration of fungicides such as triadimefon is very low, and good disease prevention effect can be achieved by dressing seeds according to the proportion of 0.03% (active ingredient) of dry seed weight. After the treatment of wheat seeds, there are often slow emergence (usually 1-2 days late emergence) and dwarfing of plants, but there is no adverse effect on seedling emergence rate, late growth and yield. If you overdose, it will lead to drug damage.

two。 Control of underground pests

Mixing wheat seeds with medicine and treating soil before sowing are the most effective measures to control wheat underground pests. Seed dressing treatment: the method of seed dressing can be used to control the general occurrence area of underground pests. You can choose 50% phoxim to mix seeds, according to 0.2% of the seed amount, that is, 100 jin of seeds with 100 grams of medicine, 2-3 kg of water, or 48% chlorpyrifos EC according to 0.3% of the seed weight. After mixing, the seeds can be sown for 4-6 hours, which can effectively control underground pests. Treatment of soil: the serious occurrence area of underground pests should be controlled by the combination of soil treatment and seed dressing. Soil treatment can be evenly spread on the ground with 3% phoxim granule 2-2.5 kg, and then turned into the soil. It can also be made into poisonous soil with 250 ml of 50% phoxim EC, 1-2 kg of water and 20 kg of fine soil mixed with 25 kg of fine soil, which is evenly scattered on the ground and then turned into the soil.

3. Control of fishy smut, total erosion and powdery mildew

Seed dressing with pesticides can not only control wheat smut, but also effectively control the occurrence and harm of wheat rust, total erosion and powdery mildew before winter, and reduce the amount of overwintering bacteria.

1) in the areas where scattered smut, fishy smut, root rot, sheath blight and total erosion occur, 40% pentachloronitrobenzene can be dry mixed with 0.5% of the weight of wheat seeds (that is, 40 grams per mu, about 8 kg of wheat) to control wheat fishy smut. You can also choose 6% tebuconazole (Likexiu) suspension bag (10 ml), add water 0.8-1 jin, seed dressing 50-70 jin, or 2.5% fluroxime (Shile) suspension for wheat seed dressing according to the recommended dose. at the same time, it can treat both autumn seedling rust and powdery mildew. Using 15% vermicellin wettable powder to mix seeds with 0.2% seed weight or 20% triadimefon EC with 5 jin of water and 500 jin of wheat seeds can prevent powdery mildew and leaf rust.

2) in the area with serious occurrence of wheat total erosion disease, 12.5% silothiamide (total erosion net) suspension can be selected for seed treatment, which has a good control effect on wheat total erosion disease. Generally use a bag of total erosion net (20 ml), first mix 300-500 ml of water, can mix 20-25 jin of seeds, mix well, sow for 6-12 hours (conducive to the exertion of the medicine and kill the germs of the seeds), dry in a cool place and sow the seeds.

(3) in the areas where wheat yellow dwarf disease and clump dwarf disease occur, imidacloprid can be used to treat seeds, control poisonous insects, control the occurrence and harm of wheat yellow dwarf disease and rosette dwarf disease, and control underground pests at the same time.

4) in the mixed occurrence area of many kinds of diseases and pests, the seed coating agent or seed dressing agent combined with fungicides and insecticides should be widely used for coating or seed treatment. All localities should choose appropriate seed coating agents or seed mixing agents according to the main types of local diseases and insect pests, and their dosage is generally the same as the effective components of a single agent in the compound (mixed) agent.

Matters needing attention

1. Determine the types of drugs according to the situation of diseases and insect pests in the place where they occur. If the occurrence of local wheat seedling pests is very light and the disease is serious, you can only use fungicides to treat seeds, but there is no need to use insecticides; if diseases and insect pests occur mixed, you should not only use insecticides to treat seeds, but also use fungicides to treat seeds; if underground pests occur seriously, seed dressing may not achieve the desired control effect, so seed dressing and soil treatment should be adopted to control wheat pests.

2. Accurately grasp the amount of pesticides. To control wheat underground pests, 50% phoxim EC can be used to control wheat diseases such as fishy smut, total erosion, powdery mildew and sheath blight, and 15% rust rather wet powder and 6% Likexiu suspension can be used to mix wheat seeds. The practice has proved that if the dosage of wheat seed dressing with strychnine and phoxim is too large, it will cause obvious drug damage to wheat, resulting in delayed emergence, slow growth, and even lack of seedlings and broken ridges in serious cases, so special attention should be paid to it.

3. Pay attention to the method of seed mixing. Wheat seed dressing with phoxim, etc., should first dilute the pesticide with water, and then mix well with wheat seeds, cover the pile and sow seeds. When wheat seeds are mixed with pentachloronitrobenzene, strychnine and Likexiu, the seeds should be sprayed to wet with clean water, then the chemicals should be evenly mixed on the seeds, and then sown immediately or after drying. If you want to mix seeds with insecticides and fungicides, you should first mix pesticides, pile up stuffy and then mix fungicides, and then sow seeds immediately.

4. You can't stay with it for a long time. After wheat seeds are mixed with insecticides, the seeds are generally stuffed for 2-3 hours, at most 5-6 hours, and sowed immediately after the medicament is absorbed by the wheat seeds. General wheat seeds with fungicides should be sowed or dried immediately after sowing.

5. It is necessary to strictly follow the operating rules of seed dressing to prevent human and animal poisoning, and it is best to implement unified seed dressing.